Structural unit.



W. H. BURK.

STRUCTURAL UNIT.

APPLICATION FILED AUG-4. 1911.

Patented July 20, 1915.

H. BURK, OF ST. LOUIS, MISSOURI.

STRUCTURAL UNIT.

Specification of Letters Patent.

Patented July 20, 1915.

Application filed August 4, 1911. Serial No. 642,297.

To all whom it may concern:

Be it known that 1, WILLIAM H. BURK, a citizen of the United States, and a resident of the city of St. Louis and State of Missouri, have invented a new and useful Improvement in Structural Units, of which the following is a specification.

Heretofore it has been proposed to stiffen expanded metal by means of longitudinal corrugations, and otherwise, for the purpose of better adapting it for use as metallic lathing and for reinforcing concrete and for like purposes. The primary value of expanded metal consists in its economy; and the difficulties of manufacture and the wasteful use of metal involved in the above mentioned proposal are suchas to defeat their point of economy.

The purpose of the present invention is to harmonize the mechanical requirements of the finished article with the requirements of the manufacturing operation so as to secure a desirable structural unit at a minimum cost.

To this end, the invention consists principally in welding the margins of strips of expanded metal to the margins of strips of sheet metal corrugated to form stifiening ribs therefor; and it also consists in the combinations and arrangements of parts hereinafter shown and described.

In the accompanying drawing wherein like symbols refer to like parts wherever they occur, Figure 1 is a plan view of a structural unit embodying my invention; Fig. 2 is a cross section thereof on the 11116 2-2 of Fig. 1 and Fig. 3 is a'bottom v1ew,

My structural unit comprises a plurality of metal strips 1 welded to the margins of a strip or strips 2 of expandedmetal. Any suitable form of expanded metal may be used for the purpose, but it is preferable to use the expanded metal in narrow strips. The metal strips 1. are preferably made of sheet metal whose middle portion 3 is crimped or corrugated longitudinally, leaving the marginal portions 4 thereof in the original plane of the sheet and thus 00115131- tuting outwardly turned flanges on the corrugated portion which, in effect, constitutes a longitudinal rib. The sheet metal strips 1 are arranged parallel with each other and with the edges of the expanded metal overlappin the flanged or marginal portlons thereo By this arrangement, the operation purpose considered from the standof welding the expanded metal flatwise to the marginal portions of the corrugated strips is greatly facilitated. Likewise, as the expanded metal is used in comparatively narrow strips and remains flat, difiiculties incident to prior inventions are eliminated. Also, as the corrugated 0r ribbed strip is originally separate from the expanded metal strip, the greatest freedom is attainable in the selection and design of the two elements to make up the unit. Obviously, the rib strips and the reticulated metal strips may be welded together before the rib strips are crimped or corrugated; and in such case, the bending of the metal to form the ribs may be within or beyond the margins of the reticulated portions. When the lines of bending are beyond the margins of the reticulated portions (as illustrated in the drawing) the reticulated sheet lies flat; but, when the lines of bending are within the margins of the reticulated portion, then such margins are inclined upwardly parallel with the sides of the ribs, and the margins of the rib portions are not flanged. In both cases, it is preferable to have the welded surfaces contact flatwise, although it is possible to weld the edges of the reticulated portions to the rib portions.

What I claim is:

1. A composite structural unit composed of a strip of expanded metal and strips of sheet metal whose edges are secured flatwise by welds to the longitudinal margins of said expanded metal, the middle portion of said sheet metal strips being crimped longitudinally to form stiflening ribs.

2. A composite structural unit comprising a strip of expanded metal and parallel strips of metal overlapping the edges thereof and secured thereto flatwise, said parallel strips comprising marginal portions lying in the same plane and a longitudinally crimped middle portion.

A- composite structural unit composed of a plurality of sheet metal strips with a strip of expanded metal intervening, each of said sheet metal strips having a flat marginal portion and a medial longitudinally corrugated portion, the edges of said expanded metal strip being superposed on and secured to the respective adjacent margins of said first mentioned strips.

4. A composite structural unit comprising a plurality of metal strips each consisting of a longitudinally crimped body portion 7 right angles thereto,

and marginal portions at approximately and a strip of expanded metal interposed between each two of said first mentioned strips the edges of said expanded metal overlapping and being in surface contact with the margins of said first mentioned strips, respectively, and connections in the form of welds between said contacting surfaces.

5.-A composite structural unit composed of a strip of expanded metal and separate strips of entire sheet metal, the edges of said entire strips being secured flatwise by welds :to the longitudinal margins of said expanded metal, the middle portion of said sheet metal strips being crimped longitudinally to form stiflening ribs.

6. A composite structure composed of strips of expanded metal and strips of sheet metal, the longitudinal margins of said strips overlapping flatwise, and a rigid connection between contiguous strips, said rigid 'connection comprising a series of isolated welds between the overlapping portions. of said strips.

7. A reinforcing element for concrete work comprising longitudinal supporting members crimped longitudinally to form stiffening ribs and having lateral and fiat projections connected by a sheet of expanded material having flat lateral edges resting on the projections aforesaid and securely attached thereto.

8. A reinforcing element for concrete work comprising longitudinal supporting members crimped longitudinally to form stiffening ribs and having. lateral and flat projections which are connected by a sheet of expanded material, the said sheet of expanded material having substantially flat lateral edges which rest upon the projections aforesaid and are secured thereto by I welds to thus produce a substantially unitary structure.

Signed at St. Louis, Mo., this'31st day of July, 1911.

WILLIAM H. BURK.

Witnesses:

JAMES A. CARR,

ALBERT H. CRoIssANT. 

